After remarking that the mathematician positively knows that the sum of the three angles of a triangle is equal to two right angles... Introduction and books 1,2 - Page 218by Euclid, Sir Thomas Little Heath, Johan Ludvig Heiberg - 1908Full view - About this book
| Laura A Knott - Jews - 1922 - 413 pages
...nearest analogy to this to-day is our attitude toward mathematical truth. In stating the fact that the **sum of the three angles of a triangle is equal to two right** angles we do not think of giving credit to the person who first discovered and announced that truth,... | |
| Charles Sanders Peirce, Justus Buchler - Philosophy - 1940 - 386 pages
...inferences. Locke explains it as follows: After remarking that the mathematician positively knows that the **sum of the three angles of a triangle is equal to two right** angles because he apprehends the geometrical proof, he thus continues: "But another man who never took... | |
| Roberto Bonola - Mathematics - 1955 - 389 pages
...not differ materially from that of SACCHEEt. We shall rather show how LEGENDEE proves that the sam **of the three angles of a triangle is equal to two right** angles. Suppose that in the triangle ABC [cf. Fig. 29] ^A + <-# + -C C< 2 right angles. A point D heing... | |
| Howard Whitley Eves - Mathematics - 1983 - 270 pages
...would you choose? 1. The three altitudes of a triangle, produced if necessary, meet in a point. 2. The **sum of the three angles of a triangle is equal to two right** angles. 3. An angle inscribed in a circle is measured by half its intercepted arc. 4. The tangents... | |
| Howard Whitley Eves - Mathematics - 1997 - 344 pages
...geometry, and why? (1) The three altitudes of a triangle, produced if necessary, meet in a point. (2) The **sum of the three angles of a triangle is equal to two right** angles. 2.1.2 A mathematics instructor is going to present the subject of geometric progressions to... | |
| Charles Sanders Peirce - Philosophy - 1923 - 318 pages
...inferences. Locke explains it as follows: After remarking that the mathematician positively knows that the **sum of the three angles of a triangle is equal to two right** angles because he apprehends the geometrical proof, he thus continues: " But another man who never... | |
| V. S. Varadarajan - Mathematics - 1998 - 142 pages
...than Euclid's Elements. Among the most famous of the theorems in the Elements are the following. The **sum of the three angles of a triangle is equal to two right** angles. The area of the square on the hypotenuse of a right angled triangle is equal to the sum of... | |
| Daniel Garber, Michael Ayers - Philosophy - 2003 - 1616 pages
...act of affirming or denying are one and the same thing. When, for example, the mind affirms that the **sum of the three angles of a triangle is equal to two right** angles, that affirmation cannot exist or be thought without the idea of a triangle. Conversely, the... | |
| Lisa M. Dolling, Arthur F. Gianelli, Glenn N. Statile - Science - 2003 - 716 pages
...geometrical figures have different properties on the different surfaces. On the sheet of paper the **sum of the three angles of a triangle is equal to two right** angles, on the egg, or the sphere, it is larger, on the saddle it is smaller. On the flat paper —... | |
| Euclid - Geometry - 1926
...respectively, the sum of the angles of the whole triangle is (zR - o) + (zR - ft ) - zR = iR - (a + 0). III. **If the sum of the three angles of a triangle is equal to two right** angles, the same is true of all triangles obtained by subdividing it by straight lines drawn from a... | |
| |